1. Field of the Invention
The present invention relates in general to a method of producing a skin-covered pad of a seat, and more particularly to a method of producing a skin-covered pad which has decorative grooves formed on a front face thereof.
2. Description of the Prior Art
Hitherto, in the field of seat manufacturing, a so-called "skin covered pad" has been widely used as a cushion member of a seat cushion and/or a seatback. The skin-covered pad is arranged on the seat structure with its front face exposed to the outside. Usually, the skin-covered pad is produced by pouring a liquid material for foamed polyurethane or the like into a bag-shaped outer skin member held in a mold, and thereafter, curing the same in a suitable manner.
In order to improve the external appearance, some of the skin-covered pads are provided at their front faces with a plurality of decorative grooves or the like.
One of the methods for producing such grooves is disclosed in Japanese Patent First Provisional Publication No. 60-160990. In this method, the decorative grooves are previously provided to the bacg-shaped outer skin member before the skin member is subjected to the molding of the polyurethane foam. That is, the bag-shaped outer skin member with the grooves is put into a mold, and thereafter, a liquid material for foamed polyurethane is poured into the skin member and cured in a known manner. In order to properly hold the skin member, the mold has at it cavity bottom a corresponding number of projections for engagement with the grooves of the skin member.
However, providing the grooves to the skin member prior to the urethane molding increases the number of production steps of the skin-covered pad. Furthermore, proper positioning of the skin member to the mold is difficult or at least troublesome due to provision of the projections on the cavity bottom of the mold. In fact, if the urethane molding is carried out with the grooves of the skin member mismatched with the corresponding projections of the mold, an inferior product is inevitably produced.